1. Field of the Invention
The present invention relates to the field of manufacture of OLED (Organic Light Emitting Diode) devices, and in particular to an ultraviolet LED (Light Emitting Diode) light source and a curving and packaging device and method for an OLED device.
2. The Related Arts
Organic light emitting diodes (OLEDs) have a variety of advantages, such as being self-luminous, low driving voltage, high luminous efficiency, shortened response time, high clarity and contrast, approximately 180° view angle, wide operation temperature range, and being capable of achieving flexible displaying and large area full color displaying, and are regarded as displaying devices having the best prosperous future of development.
In a manufacturing process of an OLED device, adhesively bonding a substrate and a lid together to achieve cured package for preventing invasion of moisture and oxygen into the interior is a technique of vital importance. The result of cured package directly affects the performance of the interior components of the OLED.
Ultraviolet (UV) curing technology is the most commonly used technique for packaging an OLED device. Irradiating liquid UV resin with ultraviolet radiation induces a cross-linking reaction occurring in the UV resin to achieve fast solidification and shaping. UV curing possesses the following advantages. No or minor solvent is used so as to reduce the environmental contamination caused by solvents. Energy consumption is small for curving can be achieved at a low temperature and application to temperature sensitive material is available. Curing speed is high and the efficiency is thus high, allowing for application in a high-speed manufacturing line, and the curing facility occupies a small floor area.
Conventional ultraviolet light sources often comprise strong ultraviolet light high-voltage mercury lamps, which are vacuum linear light sources that are made of high quality pure quartz tubes, allowing massive penetration of ultraviolet lights. The strong ultraviolet light high-voltage mercury lamps have an illumination length from 5 mm to 300 mm and an effective range of spectrum between 350-450 nm with a primary wave peak of 365 nm.
Referring to FIG. 1, which is a schematic view showing a conventional OLED device curing and packaging device, the device comprises a UV curing chamber 100, an OLED device to be packaged 200 positioned in the UV curing chamber 100, and a plurality of strong ultraviolet light high-voltage mercury lamps 300 arranged under the OLED device to be packaged 200. The plurality of strong ultraviolet light high-voltage mercury lamps 300 emits ultraviolet light that, besides irradiating a UV resin frame for packaging the OLED device, also irradiates an organic light emissive layer. The large power ultraviolet light readily damage the organic light emissive layer so as to speed up aging of the organic light emissive layer, leading to occurrence of dark spots during the operation thereof to thereby affect the performance of the OLED device and shorten the lifespan of the OLED device. Thus, the conventional OLED device curing and packaging device additionally comprises a masking plate 400 positioned between the OLED device to be packaged 200 and the plurality of strong ultraviolet light high-voltage mercury lamps 300. The arrangement of the masking plate 400 protects the organic light emissive layer and reduces the damage of the organic light emissive layer caused by irradiation of the ultraviolet light. Thus, to curve and package OLED devices of different sizes, masking plates of different sizes and thicknesses must be used and this increases the manufacturing cost.
On the other hand, the plurality of strong ultraviolet light high-voltage mercury lamps 300 is linear light sources. To achieve uniformity of the light irradiating a large-sized OLED device to be packaged 200, the distance H′ between the plurality of strong ultraviolet light high-voltage mercury lamps 300 and the OLED device to be packaged 200 is relatively large, around 60 cm, and this causes an increase of the height of a UV curing device and also greatly increase the power consumption of the strong ultraviolet light high-voltage mercury lamps, leading to a waste of energy. Further, the time period within which the strong ultraviolet light high-voltage mercury lamps are capable of emitting a sufficient UV power is often not exceeding 1500 hours so that the lifespan is relatively short.